func ExampleParse_errors() {
	for _, s := range []string{"Foo", "Bar", "Foobar"} {
		_, err := language.Parse(s)
		if err != nil {
			if inv, ok := err.(language.ValueError); ok {
				fmt.Println(inv.Subtag())
			} else {
				fmt.Println(s)
			}
		}
	}
	for _, s := range []string{"en", "aa-Uuuu", "AC", "ac-u"} {
		_, err := language.Parse(s)
		switch e := err.(type) {
		case language.ValueError:
			fmt.Printf("%s: culprit %q\n", s, e.Subtag())
		case nil:
			// No error.
		default:
			// A syntax error.
			fmt.Printf("%s: ill-formed\n", s)
		}
	}
	// Output:
	// foo
	// Foobar
	// aa-Uuuu: culprit "Uuuu"
	// AC: culprit "ac"
	// ac-u: ill-formed
}

func preferredLanguages() []language.Tag {
	var langs []language.Tag
	//	langs = append(langs, language.MustParse("es_MX"))
	nav := js.Global.Get("navigator")
	if cordova.IsMobile() {
		var wg sync.WaitGroup
		wg.Add(1)
		nav.Get("globalization").Call("getPreferredLanguage",
			func(l string) {
				defer wg.Done()
				if tag, err := language.Parse(l); err == nil {
					langs = append(langs, tag)
				}
			}, func() {
				defer wg.Done()
				// ignore any error
			})
		wg.Wait()
	}
	if languages := js.Global.Get("navigator").Get("languages"); languages != nil {
		for i := 0; i < languages.Length(); i++ {
			if tag, err := language.Parse(languages.Index(i).String()); err == nil {
				langs = append(langs, tag)
			}
		}
	}
	if tag, err := language.Parse(js.Global.Get("navigator").Get("language").String()); err == nil {
		langs = append(langs, tag)
	}
	return langs
}

// Translate one or more strings of text from a source language to a target
// language. All inputs must be in the same language.
//
// The target parameter supplies the language to translate to. The supported
// languages are listed at
// https://cloud.google.com/translate/v2/translate-reference#supported_languages.
// You can also call the SupportedLanguages method.
//
// The returned Translations appear in the same order as the inputs.
func (c *Client) Translate(ctx context.Context, inputs []string, target language.Tag, opts *Options) ([]Translation, error) {
	call := c.raw.Translations.List(inputs, target.String()).Context(ctx)
	if opts != nil {
		if s := opts.Source; s != language.Und {
			call.Source(s.String())
		}
		if f := opts.Format; f != "" {
			call.Format(string(f))
		}
		if m := opts.Model; m != "" {
			call.Model(m)
		}
	}
	res, err := call.Do()
	if err != nil {
		return nil, err
	}
	var ts []Translation
	for _, t := range res.Translations {
		var source language.Tag
		if t.DetectedSourceLanguage != "" {
			source, err = language.Parse(t.DetectedSourceLanguage)
			if err != nil {
				return nil, err
			}
		}
		ts = append(ts, Translation{
			Text:   t.TranslatedText,
			Source: source,
			Model:  t.Model,
		})
	}
	return ts, nil
}

func getLangs() (tags []language.Tag) {
	for _, t := range strings.Split(*langs, ",") {
		tag, err := language.Parse(t)
		if err != nil {
			fatalf("gotext: could not parse language %q: %v", t, err)
		}
		tags = append(tags, tag)
	}
	return tags
}

// Language returns the users language code.
// Eg. "en", "es", etc
func Language() string {
	l := locale()

	tag, err := language.Parse(l)
	if err != nil {
		return defaultLanguage
	}

	base, _ := tag.Base()

	return base.String()
}

// Region returns the users region code.
// Eg. "US", "GB", etc
func Region() string {
	l := locale()

	tag, err := language.Parse(l)
	if err != nil {
		return defaultRegion
	}

	region, _ := tag.Region()

	return region.String()
}

// Init 初始化 locale 包并返回当前系统默认的本地化语言信息。
func Init() (language.Tag, error) {
	for id, messages := range locales {
		tag := language.MustParse(id)
		for key, val := range messages {
			message.SetString(tag, key, val)
		}
	}

	localeName, err := getLocaleName()
	if err != nil {
		return language.Und, err
	}

	return language.Parse(localeName)
}

// 对一些堂量的基本检测。
func TestConsts(t *testing.T) {
	a := assert.New(t)

	a.True(version.SemVerValid(Version))
	a.True(len(Name) > 0)
	a.True(is.URL(RepoURL))
	a.True(is.URL(OfficialURL))
	a.True(len(ConfigFilename) > 0).True(strings.IndexAny(ConfigFilename, "/\\") < 0)
	a.True(len(DefaultTitle) > 0)
	a.True(len(DefaultGroupName) > 0).True(strings.IndexAny(DefaultGroupName, "/\\") < 0)
	a.True(len(Profile) > 0).True(strings.IndexAny(Profile, "/\\") < 0)

	tag, err := language.Parse(DefaultLocale)
	a.NotError(err).NotEqual(tag, language.Und)
}

// parseCollation parses XML files in the collation directory of the CLDR core.zip file.
func parseCollation(b *build.Builder) {
	d := &cldr.Decoder{}
	d.SetDirFilter("collation")
	data := decodeCLDR(d)
	for _, loc := range data.Locales() {
		x, err := data.LDML(loc)
		failOnError(err)
		if skipLang(x.Identity.Language.Type) {
			continue
		}
		cs := x.Collations.Collation
		sl := cldr.MakeSlice(&cs)
		if len(types.s) == 0 {
			sl.SelectAnyOf("type", x.Collations.Default())
		} else if !types.all {
			sl.SelectAnyOf("type", types.s...)
		}
		sl.SelectOnePerGroup("alt", altInclude())

		for _, c := range cs {
			id, err := language.Parse(loc)
			if err != nil {
				fmt.Fprintf(os.Stderr, "invalid locale: %q", err)
				continue
			}
			// Support both old- and new-style defaults.
			d := c.Type
			if x.Collations.DefaultCollation == nil {
				d = x.Collations.Default()
			} else {
				d = x.Collations.DefaultCollation.Data()
			}
			// We assume tables are being built either for search or collation,
			// but not both. For search the default is always "search".
			if d != c.Type && c.Type != "search" {
				typ := c.Type
				if len(c.Type) > 8 {
					typ = typeMap[c.Type]
				}
				id, err = id.SetTypeForKey("co", typ)
				failOnError(err)
			}
			t := b.Tailoring(id)
			c.Process(processor{t})
		}
	}
}

// TypeCheck implements the Expr interface.
func (expr *CollateExpr) TypeCheck(ctx *SemaContext, desired Type) (TypedExpr, error) {
	_, err := language.Parse(expr.Locale)
	if err != nil {
		return nil, errors.Wrapf(err, "invalid locale %s", expr.Locale)
	}
	subExpr, err := expr.Expr.TypeCheck(ctx, TypeString)
	if err != nil {
		return nil, err
	}
	switch t := subExpr.ResolvedType().(type) {
	case tString, TCollatedString:
		expr.Expr = subExpr
		expr.typ = TCollatedString{expr.Locale}
		return expr, nil
	default:
		return nil, fmt.Errorf("incompatible type for COLLATE: %s", t)
	}
}

//Read all .ini files in dir, where the filenames are BCP 47 tags
//Use the language matcher to get the best match for the locale preference
func InitI18n(locale, dir string) {
	pref := language.Make(locale) // falls back to en-US on parse error

	files, err := ioutil.ReadDir(dir)
	if err != nil {
		log.Fatal(err)
	}

	serverLangs := make([]language.Tag, 1)
	serverLangs[0] = language.AmericanEnglish // en-US fallback
	for _, file := range files {
		if filepath.Ext(file.Name()) == ".ini" {
			name := strings.TrimSuffix(file.Name(), ".ini")
			tag, err := language.Parse(name)
			if err == nil {
				serverLangs = append(serverLangs, tag)
			}
		}
	}
	matcher := language.NewMatcher(serverLangs)
	tag, _, _ := matcher.Match(pref)

	fname := filepath.Join(dir, tag.String()+".ini")
	conf, err := configparser.Read(fname)
	if err != nil {
		log.Fatal("cannot read translation file for", tag.String(), err)
	}

	formats, err := conf.Section("formats")
	if err != nil {
		log.Fatal("Cannot read formats sections in translations for", tag.String(), err)
	}
	translations, err := conf.Section("strings")
	if err != nil {
		log.Fatal("Cannot read strings sections in translations for", tag.String(), err)
	}

	i18nProvider = &i18n{
		translation_dir: dir,
		formats:         formats.Options(),
		translations:    translations.Options(),
		locale:          tag,
	}
}

// SupportedLanguages returns a list of supported languages for translation.
// The target parameter is the language to use to return localized, human
// readable names of supported languages.
func (c *Client) SupportedLanguages(ctx context.Context, target language.Tag) ([]Language, error) {
	call := c.raw.Languages.List().Context(ctx).Target(target.String())
	res, err := call.Do()
	if err != nil {
		return nil, err
	}
	var ls []Language
	for _, l := range res.Languages {
		tag, err := language.Parse(l.Language)
		if err != nil {
			return nil, err
		}
		ls = append(ls, Language{
			Name: l.Name,
			Tag:  tag,
		})
	}
	return ls, nil
}

// DetectLanguage attempts to determine the language of the inputs. Each input
// string may be in a different language.
//
// Each slice of Detections in the return value corresponds with one input
// string. A slice of Detections holds multiple hypotheses for the language of
// a single input string.
func (c *Client) DetectLanguage(ctx context.Context, inputs []string) ([][]Detection, error) {
	call := c.raw.Detections.List(inputs).Context(ctx)
	res, err := call.Do()
	if err != nil {
		return nil, err
	}
	var result [][]Detection
	for _, raws := range res.Detections {
		var ds []Detection
		for _, rd := range raws {
			tag, err := language.Parse(rd.Language)
			if err != nil {
				return nil, err
			}
			ds = append(ds, Detection{
				Language:   tag,
				Confidence: rd.Confidence,
				IsReliable: rd.IsReliable,
			})
		}
		result = append(result, ds)
	}
	return result, nil
}

func newColumnTableDef(
	name Name, typ ColumnType, qualifications []NamedColumnQualification,
) (*ColumnTableDef, error) {
	d := &ColumnTableDef{
		Name: name,
		Type: typ,
	}
	d.Nullable.Nullability = SilentNull
	for _, c := range qualifications {
		switch t := c.Qualification.(type) {
		case ColumnCollation:
			locale := string(t)
			_, err := language.Parse(locale)
			if err != nil {
				return nil, errors.Wrapf(err, "invalid locale %s", locale)
			}
			switch s := d.Type.(type) {
			case *StringColType:
				d.Type = &CollatedStringColType{s.Name, s.N, locale}
			case *CollatedStringColType:
				return nil, errors.Errorf("multiple COLLATE declarations for column %q", name)
			default:
				return nil, errors.Errorf("COLLATE declaration for non-string-typed column %q", name)
			}
		case *ColumnDefault:
			if d.HasDefaultExpr() {
				return nil, errors.Errorf("multiple default values specified for column %q", name)
			}
			d.DefaultExpr.Expr = t.Expr
			d.DefaultExpr.ConstraintName = c.Name
		case NotNullConstraint:
			if d.Nullable.Nullability == Null {
				return nil, errors.Errorf("conflicting NULL/NOT NULL declarations for column %q", name)
			}
			d.Nullable.Nullability = NotNull
			d.Nullable.ConstraintName = c.Name
		case NullConstraint:
			if d.Nullable.Nullability == NotNull {
				return nil, errors.Errorf("conflicting NULL/NOT NULL declarations for column %q", name)
			}
			d.Nullable.Nullability = Null
			d.Nullable.ConstraintName = c.Name
		case PrimaryKeyConstraint:
			d.PrimaryKey = true
			d.UniqueConstraintName = c.Name
		case UniqueConstraint:
			d.Unique = true
			d.UniqueConstraintName = c.Name
		case *ColumnCheckConstraint:
			d.CheckExprs = append(d.CheckExprs, ColumnTableDefCheckExpr{
				Expr:           t.Expr,
				ConstraintName: c.Name,
			})
		case *ColumnFKConstraint:
			if d.HasFKConstraint() {
				return nil, errors.Errorf("multiple foreign key constraints specified for column %q", name)
			}
			d.References.Table = t.Table
			d.References.Col = t.Col
			d.References.ConstraintName = c.Name
		case *ColumnFamilyConstraint:
			if d.HasColumnFamily() {
				return nil, errors.Errorf("multiple column families specified for column %q", name)
			}
			d.Family.Name = t.Family
			d.Family.Create = t.Create
			d.Family.IfNotExists = t.IfNotExists
		default:
			panic(fmt.Sprintf("unexpected column qualification: %T", c))
		}
	}
	return d, nil
}

// GetLocale creates a new language Tag from a locale
func GetLocaleTag(locale string) (language.Tag, error) {
	return language.Parse(locale)
}

func checkLocale(locale string) error {
	_, err := language.Parse(locale)
	return err
}

func main() {
	tag, err := locale.Init()
	if err != nil {
		warn.Println(err)
		info.Println("无法获取系统语言，使用默认的本化语言：", app.DefaultLocale)
		tag, err = language.Parse(app.DefaultLocale)
		if err != nil {
			erro.Println(err)
			return
		}
	}
	locale.SetLocale(tag)

	h := flag.Bool("h", false, locale.Sprintf(locale.FlagHUsage))
	v := flag.Bool("v", false, locale.Sprintf(locale.FlagVUsage))
	l := flag.Bool("l", false, locale.Sprintf(locale.FlagLUsage))
	g := flag.Bool("g", false, locale.Sprintf(locale.FlagGUsage))
	pprofType := flag.String("pprof", "", locale.Sprintf(locale.FlagPprofUsage))
	flag.Usage = usage
	flag.Parse()

	switch {
	case *h:
		flag.Usage()
		return
	case *v:
		locale.Printf(locale.FlagVersionBuildWith, app.Name, app.Version, runtime.Version())
		return
	case *l:
		locale.Printf(locale.FlagSupportedLangs, input.Langs())
		return
	case *g:
		path, err := getConfigFile()
		if err != nil {
			erro.Println(err)
			return
		}
		if err = genConfigFile(path); err != nil {
			erro.Println(err)
			return
		}
		info.Println(locale.Sprintf(locale.FlagConfigWritedSuccess, path))
		return
	}

	// 指定了 pprof 参数
	if len(*pprofType) > 0 {
		profile := filepath.Join("./", app.Profile)
		f, err := os.Create(profile)
		if err != nil { // 不能创建文件，则忽略 pprof 相关操作
			warn.Println(err)
			goto RUN
		}
		defer func() {
			if err = f.Close(); err != nil {
				erro.Println(err)
				return
			}
			info.Println(locale.Sprintf(locale.FlagPprofWritedSuccess, profile))
		}()

		switch strings.ToLower(*pprofType) {
		case "mem":
			defer func() {
				if err = pprof.Lookup("heap").WriteTo(f, 1); err != nil {
					warn.Println(err)
				}
			}()
		case "cpu":
			if err := pprof.StartCPUProfile(f); err != nil {
				warn.Println(err)
			}
			defer pprof.StopCPUProfile()
		default:
			erro.Println(locale.Sprintf(locale.FlagInvalidPprrof))
			return
		}
	}

RUN:
	run()
}